Known touch switches are generally classified into types that detect a change in light, and types that detect a change in electrical characteristic. Touch switches based on change in electrical characteristic include capacitive coupling touch switches. Patent Document 1 discloses an example of a capacitive coupling touch switch in which a plurality of sensor electrodes is laid out on a substrate. Each sensor electrode is connected to a conductive wire (wire portion) that is connected to a capacitance detection circuit. When a user touches one of the sensor electrodes with a finger, the capacitance detection circuit detects the capacitance change due to the capacitance of the human body, thereby specifying the touched position. At this time, by detecting the value of the electric current in the sensor electrode, it is possible to calculate the touched position.